Tl;dr
We wanted to do squadplay, found a group of nice guys, joined their teamspeak, one was hacking and used this to his advantage.

His Steam: https://steamcommunity.com/id/skillfulpistol
As you can see he is a regular cheater on multiple games (6 VAC Bans)
I have no proof, but please look into it.
Our plan was to meet up at NWAF, and when we joined Teamspeak we hear him say "Wow I can freecam to them","I just teleported to a really S**t place."

Also, they were all at NWAF, and he was behind us while we were on our way there before even telling them we have left for NWAF. He then killed my friend and 'ran away'.

I know the information isn't the best, but I hate hackers/cheaters with a passion.
Thanks.